Casting-mold.



N0. 694,566. Patented Mar. 4, |902.

- S. MICHAILUFF.

CASTING MOLD.

(Application: med In'. 16, 1901.)

(lo Model.)

oq /o QQX50 oo o o MS o UNITED STATES PATENT OFFICE.

SSEMON MICHAILOFF, OF ODESSA, RUSSIA.

CASTING-MOLD.

SPECIFICATION forming part of Letters Patent No. 694,566, dated March 4, 1902.

Application filed March 16, 1901. Serial No. 51.529. (No mndeLl To all whom t may concern,.-

Be it knownthat 1, SsEMoN MIcHAILoFF, a subject of the Emperor of Russia, residing at Choutorskaya oulitze, No. 48 50, Odessa,

A further object of this invention 'is to close the joints of the parts of the mold in such a way that no casting can be formed therein, and the formation of fins, the subsequent chipping, filling, or rumbling the casting is obviated, so that the object when taken from the mold in a glowing condition can be coated when sufficiently cooled with the protecting layer of tar without any further treatment.

These objects are attained by the hereinafter-described method by using special material for the inmost layer of the mold and by securing the mold to the flask, using properlyshaped tie-bars rigidly connected to and suitably spaced in the Hask.

Referring 'to the drawings, in which like parts are similarly designated, Figure l is a cross-section of the finished mold; and Fig. 2 a section on line A B, Fig. 1, illustrating the various stages in building the moldin the flask.

The flask is here shown as made in two parts 4 and 5, provided with strengthening-ribs 6 and flanges 7 at the meeting edges of the parts of the flask. Through these flanges are passed securing-bolts 8, that hold the parts of the flask together. The body of the flask is provided with suitable vents in the form of perforations 9 for the escape of gases through the mold. On the interior of the flask are rigidly secured the bars 10, provided with pins 11, that aid in holding the material of the mold in place.

In Fig. 2 I have shown in section ailask and the various stages of the mold, the part C D showing the interior of the bare flask and the vents 9; D E, the anchors or retaining-pins rigidly secured thereto; E F, a foundationlayer 13 of the mold,with a substantially dovetailed groove 12 formed therein, only tops or tangential. portions of the pins 11 being visible; -F F', the mold, comprising two foundation-layers 13 and 13, with the inner thin layer 14, and F G the finished mold.

According to myA invention a rough mold is formed of a pasty mass, consisting of the ordinary materials used in dry sand and loam molding, mixed in the usual manner with wa` ter, and it may be with some boiled oil, which is placed in the flask with trowels. The rough mold is made in the ordinary manner by applying the material in one, two, or more layers, each layer being dried before the other is applied. When two layers are used, the following method is preferred: A mixture of loam clay and line-chopped straw is'stirred with water to form a stiff paste and is spread in a suitable thickness over the walls of the flask or casting-box (about half the. thickness of the Wall of the mold) and is then dried or fired. A second layer of approximately the same thickness'is then applied, so as to substantially cover the remain- Aingfpor'tions of the right-angled metallic hooks,

(tie -bars,) rigidly secured to thev flask, as shown, between EF, Fig. 2, consisting of refractory clay, sand, and horse droppings, taken in about equal proportions, ground, and stirred with water and boiled oil to form a plastic mass. After drying by hot air or furnace-gases this layer is covered by a thin one (three to four millimeters) of' a sticky pasty material, as shown at F F', Fig. 2, which forms after drying a crust as hard as stone and adheres firmly to the material of the rough mold, but does not adhere to the molten or solidifying metal. Owing to these properties, the inmost layer of the mold is extraordinarily durable in spite of its very slight thickness, and a mold is produced which can be used many times with very slight repairs of this inmost layer by applying to the injured parts some fresh material, which gets dry at once by the heat of the mold. The material for this inmost layer is prepared by grinding and mixing about forty per cent. of burnt refractory clay, (terra-cotta powder,) fifteen per cent.- of burnt crucible graphite, ten per cent. of fatty clay, fifteen per cent. of washed sand, (river- IOO sand,) [ive per cent. of charcoal, and fifteen per cent. of cow-dung, with water and boiled linseed-oil, taken in the proportion of about three toone and in such a quantityas will be necessary to produce a sticky pappy material. Former-boards are used to remove the excess of this material. In order to finish the mold, there remains only to dry or fire the same by means of furnace-gases, hot air, or the like, and to paint or dust the surface of the finished mold with a coat of graphite in the usual manner. If the mold is to be composed of two or more parts, the joints are closed, so as to obviate the forming of casting-seams by means of the fresh (not dried) lnaterial of the inmost thin layer that fills the small trapezium-shaped or dovetailed grooves l2, left along the inner edge of one of the surfaces of the parts of the mold at thejoints, so that when these surfaces strike together the excess of filling material is squeezed out of the grooves in the mold and a perfect joint is obtained. These grooves are lnade While the material is plastic by making a depression along the edge with a trowel or board. The excess of jointing material which exudes from the mold is linally rcmoved by means of a scraper or the like, when the dried portions of the mold are united and before casting to produce a continuous internal surface and to unite the parts, as shown at F F, Fig. 2.

Having now described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. A mold consisting` of separable parts each composed of a number of layers of material of different porosity, the meeting edges of the parts combiningto form a dovetail groove and a filling material in said grooves to form a continuous inner surface with the inner layer, substantially as described.

2. A casting-mold comprising a foundation of molding material and a coating of a mixture of burnt clay, Crucible-graphite, fat clay,

sand, charcoal and cow-dung, substantially as described.

A casting-mold comprising a foundation of molding material mixed with boiled oil and a coating of a mixture of burnt clay, crucible-graphite, fat clay, sand, charcoal, cowdung, Water and boiled oil, substantially as described.

4. A casting-mold comprising a foundation of molding material mixed with boiled oil and formed in separable parts, and a coating of a mixture of burnt clay, erucible-graphite, fat clay, sand, charcoal, and cow-dung, substantially as described.

5. A casting-mold comprising a layer of a mixture of lean clayand chopped straw, a second layer of a mixture of burnt clay, sand, horse-droppings,oil and Waterand a thin layer of burnt clay, crucible-graphite,fatelay, sand, and charcoal, cow-dung, substantially as described.

G. A casting-mold, comprising one or more foundation-layers of a suitable material and a coating of a mixture of burnt clay, cruciblegraphite, fat clay, sand, charcoal, cow-dung and linseed-oil, to be subsequently burnt or fired, substantially as described.

7. A casting-mold, comprising one or more foundation-layers of a suitable material Whose meeting edges form dovetailed grooves and a coating of a mixture of forty per cent.'burnt refractory clay, fifteen per cent. burnt crucible-graphite, ten per cent. fat clay, fifteen per cent. sand, five per cent. charcoal and fifteen per cent. cow-dung mixed with Water and boiled linseed-oil, to be subsequently baked or fired, substantially as described.

In testimony that I claim the foregoing as my invention I have signed my name in presence of tivo subscribing Witnesses.

SSEMON MICIIAILOFF.

Witnesses:

PAUL ZARITSKI, V. DiDENKo. 

